[tip: locking/core] locking/arch: Wire up local_try_cmpxchg

From: tip-bot2 for Uros Bizjak
Date: Thu Apr 13 2023 - 07:38:45 EST


The following commit has been merged into the locking/core branch of tip:

Commit-ID: 62de78f1c39a6b3f456e9dfe000b3d92b9a58ee4
Gitweb: https://git.kernel.org/tip/62de78f1c39a6b3f456e9dfe000b3d92b9a58ee4
Author: Uros Bizjak <ubizjak@xxxxxxxxx>
AuthorDate: Wed, 05 Apr 2023 16:17:08 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Wed, 12 Apr 2023 16:46:34 +02:00

locking/arch: Wire up local_try_cmpxchg

Implement target specific support for local_try_cmpxchg
and local_cmpxchg using typed C wrappers that call their
_local counterpart and provide additional checking of
their input arguments.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230405141710.3551-4-ubizjak@xxxxxxxxx
---
arch/alpha/include/asm/local.h | 12 ++++++++++--
arch/loongarch/include/asm/local.h | 13 +++++++++++--
arch/mips/include/asm/local.h | 13 +++++++++++--
arch/powerpc/include/asm/local.h | 11 +++++++++++
arch/x86/include/asm/local.h | 13 +++++++++++--
5 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/arch/alpha/include/asm/local.h b/arch/alpha/include/asm/local.h
index fab26a1..0fcaad6 100644
--- a/arch/alpha/include/asm/local.h
+++ b/arch/alpha/include/asm/local.h
@@ -52,8 +52,16 @@ static __inline__ long local_sub_return(long i, local_t * l)
return result;
}

-#define local_cmpxchg(l, o, n) \
- (cmpxchg_local(&((l)->a.counter), (o), (n)))
+static __inline__ long local_cmpxchg(local_t *l, long old, long new)
+{
+ return cmpxchg_local(&l->a.counter, old, new);
+}
+
+static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
+{
+ return try_cmpxchg_local(&l->a.counter, (s64 *)old, new);
+}
+
#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))

/**
diff --git a/arch/loongarch/include/asm/local.h b/arch/loongarch/include/asm/local.h
index 65fbbae..83e995b 100644
--- a/arch/loongarch/include/asm/local.h
+++ b/arch/loongarch/include/asm/local.h
@@ -56,8 +56,17 @@ static inline long local_sub_return(long i, local_t *l)
return result;
}

-#define local_cmpxchg(l, o, n) \
- ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
+static inline long local_cmpxchg(local_t *l, long old, long new)
+{
+ return cmpxchg_local(&l->a.counter, old, new);
+}
+
+static inline bool local_try_cmpxchg(local_t *l, long *old, long new)
+{
+ typeof(l->a.counter) *__old = (typeof(l->a.counter) *) old;
+ return try_cmpxchg_local(&l->a.counter, __old, new);
+}
+
#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))

/**
diff --git a/arch/mips/include/asm/local.h b/arch/mips/include/asm/local.h
index 08366b1..5daf6fe 100644
--- a/arch/mips/include/asm/local.h
+++ b/arch/mips/include/asm/local.h
@@ -94,8 +94,17 @@ static __inline__ long local_sub_return(long i, local_t * l)
return result;
}

-#define local_cmpxchg(l, o, n) \
- ((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
+static __inline__ long local_cmpxchg(local_t *l, long old, long new)
+{
+ return cmpxchg_local(&l->a.counter, old, new);
+}
+
+static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
+{
+ typeof(l->a.counter) *__old = (typeof(l->a.counter) *) old;
+ return try_cmpxchg_local(&l->a.counter, __old, new);
+}
+
#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))

/**
diff --git a/arch/powerpc/include/asm/local.h b/arch/powerpc/include/asm/local.h
index bc4bd19..45492fb 100644
--- a/arch/powerpc/include/asm/local.h
+++ b/arch/powerpc/include/asm/local.h
@@ -90,6 +90,17 @@ static __inline__ long local_cmpxchg(local_t *l, long o, long n)
return t;
}

+static __inline__ bool local_try_cmpxchg(local_t *l, long *po, long n)
+{
+ long o = *po, r;
+
+ r = local_cmpxchg(l, o, n);
+ if (unlikely(r != o))
+ *po = r;
+
+ return likely(r == o);
+}
+
static __inline__ long local_xchg(local_t *l, long n)
{
long t;
diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
index 349a47a..56d4ef6 100644
--- a/arch/x86/include/asm/local.h
+++ b/arch/x86/include/asm/local.h
@@ -120,8 +120,17 @@ static inline long local_sub_return(long i, local_t *l)
#define local_inc_return(l) (local_add_return(1, l))
#define local_dec_return(l) (local_sub_return(1, l))

-#define local_cmpxchg(l, o, n) \
- (cmpxchg_local(&((l)->a.counter), (o), (n)))
+static inline long local_cmpxchg(local_t *l, long old, long new)
+{
+ return cmpxchg_local(&l->a.counter, old, new);
+}
+
+static inline bool local_try_cmpxchg(local_t *l, long *old, long new)
+{
+ typeof(l->a.counter) *__old = (typeof(l->a.counter) *) old;
+ return try_cmpxchg_local(&l->a.counter, __old, new);
+}
+
/* Always has a lock prefix */
#define local_xchg(l, n) (xchg(&((l)->a.counter), (n)))